Tunneling field-effect transistors (TFETs) have emerged in recent years as a direct competition to the metal-oxide semiconductor field-effect transistors (MOSFETs) due to their steep substhreshold swing (SS) of less than 60 mV/decade, which is the scaling limit of MOSFETs. A steep SS at means that a lower voltage is needed to turn on the transistor. As a result, TFETs are capable of operating at low supply voltage (VDD) as compared to MOSFETs.
However, a drawback of TFETs is that TFETs has a lower on-state current (ION) than MOSFETs at the same channel length. This is due to the large band-to-band tunneling barrier (BTBT) which governs the tunneling probability. An increase in the tunneling probability is therefore needed to obtain a higher ION and enhance the performance of the TFETs.
Therefore, there is a need to provide methods of fabricating TFETs having enhanced performance.